Hey everyone, just like there is a function named "Serial.available()" in Arduino,is there any such function present in STM32 ?

Hello everyone, I am trying to make a UART Communication between STM32 NUCLEO-L476RG and ESP32 S3. The STM must send data to ESP and the ESP must print it on Serial Monitor of Arduino IDE. However, this doesn't happen, even though I have double check...